A blood culture is a test done to see if a bacterial or fungal infection has spread to your bloodstream. The blood culture allows your healthcare provider to identify the specific bacteria or fungus causing the infection. Because an infection in the blood can be very serious infection, it is important to know what kind of bacteria or fungus is causing it and what medicine will best treat the infection.
Usually this test is done when you have signs of an infection and your provider suspects the infection may have spread to your blood.
Make sure your healthcare provider knows about any medicines (especially antibiotics), herbs, or supplements that you are taking. Don't stop any of your regular medicines without first consulting your healthcare provider.
The skin on your arm is cleaned very well and then a small amount of blood is taken from your arm with a needle. Blood may be taken from more than 1 site. The blood is collected in tubes and sent to a lab.
Having this test will take just a few minutes of your time.
Ask your health care provider when and how you will get the result of your test.
A blood culture test is positive if a bacteria or fungus grows in the culture. It is negative if nothing grows. If the test is negative, your healthcare provider may recommend that the test be repeated in several hours or days.
There are 2 possibilities when the test is positive. The first is that the bacteria or fungus grown in the blood culture are from an infection in your blood. This is most likely if you are very ill. The second possibility is that bacteria or fungus found in the blood culture are contaminants from your skin and were not actually in your blood. Your healthcare provider will decide whether or not the organisms grown in the culture are contaminants.
If the test is positive, different antibiotics will be tested in the lab to see which medicine will best treat the infection.
Test results are only one part of a larger picture that takes into account your medical history and current health. Sometimes a test needs to be repeated to check the first result. Talk to your healthcare provider about your result and ask questions. If your test results are not normal, ask your healthcare provider:
